This invention relates to the art of supplying oxygen for therapeutic use, and more particularly to a new and improved apparatus for supplying such oxygen to passengers on board aircraft.
Individuals suffering from diseases such as chronic obstructive pulmonary disease (COPD) or emphysema benefit from the administration of an oxygen rich gas stream. The source of this oxygen rich gas stream is normally high pressure cylinders, containerized liquid or chemical means, i.e. chlorate candle. Each of these methods involves the storage of relatively high volumes of oxygen. This represents a potential safety hazard in that oxygen has the effect of lowering the ignition temperature of material with which it comes in contact. High pressure cylinders present an additional safety concern being stored in excess of 2000 psig as well as being very bulky and heavy. Cryogenic oxygen is also potentially dangerous since it is stored at -297.degree. F. and requires frequent refilling due to continuous boil off. Chemical oxygen is liberated as result of the virtual ignition of various chemical compounds and is useful as an oxygen supply only for short intervals, i.e. about 20 minutes.
Individuals requiring oxygen treatment who wish to travel by aircraft must request the airline to supply it in sufficient quantity to satisfy their prescription. Airlines have an obligation to supply the same at an agreed upon fixed cost regardless of the duration of flight. The aforementioned means of supply are very costly and space consuming. With world attention becoming increasingly focused on the needs of the disabled, there is a need for airlines to make oxygen therapy readily available to those requiring it.
It would, therefore, be highly desirable to provide an apparatus and method for supplying oxygen to passengers on aircraft on an as needed basis without storing it at high pressure, extremely low temperature or in very limited quantity. In providing such apparatus and method, important considerations involve using raw material, i.e. cabin air, and operating energy, i.e. electricity, already present in the aircraft, and in a manner not presenting any safety hazard while the aircraft is in operation. In addition, such apparatus desirably will be small in size so as to be portable and locatable under passenger seats during use and which can remain on the aircraft after the passengers depart.